United States of America

The United States of America (commonly referred to as the United States, U.S., USA, or America), is a federal republic composed of 50 states, a federal district of Washington, D.C., five major territories, and various possessions. The 48 contiguous states and Washington, D.C., are in central North America between Canada and Mexico. The state of Alaska is in the northwestern part of North America and the state of Hawaii is an archipelago in the mid-Pacific. The territories are scattered about the Pacific Ocean and the Caribbean Sea. At 3.8 million square miles and with over 320 million people, the country is the world's third largest by total area (fourth largest by land area) and the third most populous. It is one of the world's most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries. The geography and climate of the United States are also extremely diverse, and the country is home to a wide variety of wildlife.

The United States is a developed country and has the world's largest national economy by nominal and real GDP, benefiting from an abundance of natural resources and high worker productivity.[34] While the U.S. economy is considered post-industrial, the country continues to be one of the world's largest manufacturers. Accounting for 34% of global military spending and 23% of world GDP, it is the world's foremost military and economic power, a prominent political and cultural force, and a leader in scientific research and technological innovations.